The taxonomy of the ocean sunfishes (Molidae) has a complicated history. Currently, three genera and four species are recognized, including two in the genus Mola (M. mola and M. ramsayi). In 2009, a genetic study revealed a potential third species, Mola species C, in Southeast Australian waters. Concentrating on this region, we obtained samples and morphological data from 27 Mola sp. C specimens, genetically confirmed the existence of this species (mtDNA D-loop and cytochrome c oxidase 1), and established its morphology across a size spectrum of 50–242 cm total length. Mola sp. C is diagnosed by clavus meristics [15–17 fin rays (13–15 principal, 2 minor), 5–7 ossicles, paraxial ossicles separate], clavus morphology (prominent smooth band back-fold, rounded clavus edge with an indent), and body scale morphology (raised conical midpoints, non-branching). This species does not develop a protruding snout, or swollen dorso- or ventrolateral ridges. Body proportions remain similar with growth. A review of the historic literature revealed that Mola sp. C is a new, hitherto undescribed species, Mola tecta, which we describe and diagnose, and that it is the first proposed addition to the genus Mola in 125 years. Its core distribution is likely in the temperate waters of the Southern Hemisphere.Keywords: Australia, CO1 mtDNA, D-loop, morphology, morphometrics, New Zealand, phylogenetics, southern hemisphere, taxonomy.

Distribution: Currently thought to be widely distributed
in all the world’s oceans except for the polar seas,
however may be relatively uncommon in some areas
(e.g. around Australia and New Zealand). • Mola ramsayi (Giglioli, 1883)

Holotype: BMNH
1883.11.29.22

Distribution: Previously thought to be restricted to the
South Pacific (Fraser-Brunner, 1951), however if Mola
sp. A is shown to belong to M. ramsayi, the distribution
is much wider than previously thought, including the
Pacific and Indian oceans in both hemispheres, as well as
the Mediterranean and probably also the European seas.

Mola tecta stranded on Birdlings Flat south of Christchurch, New Zealand, May 2014.

Photograph by M. NYEGAARD

The hoodwinker sunfish grows to at least 2.4 metres long, with a distinctive ‘backfold’ of smooth skin separating the back fin into two.

Etymology: The species name tecta is derived from the Latin tectus (disguised, hidden), as this species evaded discovery for nearly three centuries, despite the keen interest among early sunfish taxonomists and the continued attention these curious fish receive. The Japanese name is derived from the species name tecta: ‘hidden’ (Kakure), ‘sunfish’ (manbo), while the English name, ‘Hoodwinker’, pertains to the figurative meaning ‘trickster, deceiving by disguise’, c. 1600.

Habitat and distribution: Mola tecta has been
confirmed in the southeast of Australia (New South
Wales, South Australia, Tasmania and Victoria)
(Yoshita et al., 2009; this study), around New Zealand
(this study), and off South Africa (Bass et al., 2005)
(Fig. 10). Photographs (e.g. Supporting Information,
Fig. S1A) indicates that it also occurs in Chilean
waters. This suggests that M. tecta is distributed
widely in the temperate waters of the Southern
Hemisphere, with occasional, but presumably rare,
occurrences in the Northern Hemisphere. Migrations are
unknown.